Sensory-motor performance decrements in the elderly have been well-documented. While many investigators have postulated that deficits in selective attention underlie these progressive changes, definitive evidence has yet to be provided. We propose a series of experiments to assess certain attentional and cognitive capabilities of older persons using electrophysiological measures recorded from the scalp. On the basis of normative work with young adults in our laboratory and elsewhere, we plan to assess four main types of event-related brain potentials (ERPs) in an elderly subject population. Each of these ERP components has been associated with a different aspect of selective attention: (1) the N1 wave (reflecting the focussing of attention on one source of sensory information); (2) the P3 wave (associated with decision making); (3) the P3a qave (signifying the perception of deviations in a monotonous background); and (4) the "novelty"-P3 wave (elicited when a subject is surprised by a novel visual stimulus). Using these ERP techniques (together with converging behavioral measures of attention), we hope to characterize the attentional capacities of normal, elderly people. These studies will lay the groundwork for future investigations of clinical syndromes associated with aging and senescence where attentional deficits may be a dominant feature.